DELL N3000 User Manual

Configuring Link Aggregation

If VRRP is enabled on a VLAN that has an MLAG port as its member, both 

VRRP routers become VRRP masters operationally in the VLAN. This is to 

allow load balancing of the northbound L3 traffic on the MLAG.
Since the peer-link is a member of the same routing VLANs as all MLAGs, 

both the primary and secondary MLAG routers see VRRP advertisements 

sent by the other router. The internal switch packet filters are modified to 

drop VRRP advertisement packets if they are received on a VLAN that has an 

MLAG as its member. This ensures that both MLAG devices become VRRP 

Masters.
Consider the scenario in Figure 28-17.

When L3 data is received by the MLAG primary switch destined to A, P 

would trigger an ARP request to learn A's MAC address. In this case, the ARP 

request originated by P would have its interface MAC address as the source 

MAC address (MAC-P, for example) and interface IP address as the source IP 

address. If the ARP reply from A, with destination MAC address as MAC-P, is 

hashed to S, the packet will be forwarded by S to P over the peer-link so that P 

can learn A's MAC address. This requires that the virtual IP address of the 

peers. This is to ensure that packets generated by either of the MLAG peers is 

S2

A

B

R1